Handling of stacked substrates

ABSTRACT

A pneumatic device for transporting a substrate during a manufacturing operation is described. The pneumatic device can include multiple suction assemblies for securely coupling the substrate to the pneumatic device. The vertical position of the suction assemblies can be varied so that when vacuum is applied through the suction assemblies to the substrate, the substrate is in a bent configuration when secured to the pneumatic device. When the pneumatic device is used to lift the substrate off a stack of other substrates, the bending of the substrate reduces the surface area contact and likelihood of inadvertently removing additional substrates from the stack of substrates.

BACKGROUND

In certain types of manufacturing operations, lifting a sheet-like component from a stack of similar components can be problematic on account of the sheet-like components having a tendency of sticking together. When the components stick together a traditional vacuum-based manipulating tool such as a pick and place can remove too many of the components. In some cases, the additional components can fall to the floor while the manipulating tool is moving the components. Consequently, a reliable way of removing a single sheet-like component from a stack of similar sheet-like components is desired.

SUMMARY

This disclosure describes various embodiments that relate to the use of a pneumatic device for reliably transporting substrates from one area to another.

A pneumatic device for lifting, moving and releasing a substrate is disclosed. The pneumatic device is configured to lift the substrate using multiple suction assemblies. The suction assemblies can be pressed against a surface of the substrate to secure the suction assemblies to the surface thereof. In some embodiments, one or more of the suction assemblies can include a pneumatic tube for drawing air through an opening in the suction assembly. In this way, the suction assemblies that include pneumatic tubes can be attached by vacuum to the substrate.

The suction assemblies can be spring-loaded suction assemblies configured to engage the substrate with varying amounts of force. The force variation can be achieved by arranging the suction assemblies so that a first group of the spring-loaded suction assemblies contacts the substrate after a second group of the spring-loaded suction assemblies. This causes springs of the second group to be compressed farther than the springs of the first group, thereby resulting in a greater amount of force being applied by the springs of the second group. When the substrate is flexible enough to bend, this variation in force causes the regions contacted by the second group of spring-loaded suction assemblies to be forced farther away from the pneumatic device than the rest of the substrate. In this way, the substrate is placed in a bent state.

In some embodiments, the suction assemblies can be positioned by and secured within openings defined by a substantially planar plate. The suction assemblies can include vertical adjustment features that allow the vertical position of the suction assembly with respect to the substantially planar plate to be shifted to achieve a desired position.

In some embodiments, a curved plate can be utilized to support the suction assemblies. Instead of altering the vertical position of the suction assemblies with respect to the plate, the curvature of the plate can be used to define the amount of vertical standoff there is between each of the suction assemblies.

In some embodiments, one or more the spring-loaded suction assemblies in the second group can be replaced by pushing assemblies that do not include any type of suction element but are operable to push a central portion of the substrate away from the pneumatic device while the substrate is being held by the pneumatic device.

The bent state of the substrate, achieved by securing the pneumatic device to the substrate, reduces the amount of surface area contact between the substrate and any other components beneath it. This reduction in surface area contact can reduce the likelihood of the substrate remaining temporarily coupled to any other components positioned beneath it. Examples of forces that could cause a temporary coupling dependent on surface area contact include static friction and condensation.

Other aspects and advantages of the invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the described embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure will be readily understood by the following detailed description in conjunction with the accompanying drawings, wherein like reference numerals designate like structural assemblies, and in which:

FIG. 1 shows a perspective view of a manufacturing line configured to transport stacks of substrates from one location to another;

FIGS. 2A-2B show perspective views of a pneumatic device associated with the manufacturing line lifting a substrate off a stack of substrates;

FIGS. 3A-3D show height adjustment mechanisms cooperating with stack holders to keep the top of the stack of substrates in a consistent position;

FIG. 4A-4D show front views of the pneumatic device as it picks up a substrate;

FIGS. 5A-5D show multiple views of an exemplary suction assembly that is suitable for use with the described embodiments;

FIGS. 6A-6D show alternative ways in which a pneumatic device can be used to lift a substrate off a stack of other substrates; and

FIG. 7 shows a flow chart depicting a method for utilizing a pneumatic device to sequentially remove substrates from a stack of substrates.

Other aspects and advantages of the invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the described embodiments.

DETAILED DESCRIPTION

In the following detailed description, references are made to the accompanying drawings, which form a part of the description and in which are shown, by way of illustration, specific embodiments in accordance with the described embodiments. Although these embodiments are described in sufficient detail to enable one skilled in the art to practice them, it is understood that these examples are not limiting; other embodiments may be used, and changes may be made without departing from the spirit and scope of the described embodiments.

During a process for manufacturing solar cells, component manipulation can be carried out by many different types of devices. Such devices include pick and place robots, conveyors, stackers, unstackers and pneumatic devices. Pneumatic devices are commonly used to manipulate components and can be adapted to maneuver and reorient the components during manufacturing operations. The pneumatic devices can include an attachment feature that can take the form of suction assemblies. The suction assembly can define a channel through which suction can be applied until the component is firmly attached to the portion of the pneumatic device that defines one end of the channel, at which point negative pressure generated by the suction maintains the component securely against the pneumatic device. Once the pneumatic device has finished transporting the component to its intended destination, the suction generated by the pneumatic device can be turned off allowing the component to be released from the pneumatic device.

Unfortunately, conventional pneumatic devices have a number of limitations. In particular, because some pneumatic devices often attach to a top surface of a component, the bottom surface of the component remains unsupported while the component is transported from one location to another. For this reason, any item temporarily coupled to the bottom of the component is subjected to gravitational forces as well as any additional forces generated by movement of the pneumatic device. This can be problematic when a pneumatic device is used to remove a sheet-like component from a stack of similar sheet-like components. A sheet-like component can be any substrate having substantially larger top and bottom surfaces than lateral surfaces. On account of the large surface area contact between the sheet-like components of the stack, static friction, condensation and/or other surface area dependent phenomenon can temporarily couple the top component to one or more of the components beneath it. When the pneumatic device lifts the top component off the stack, static friction or condensation can cause one or more of the other similar components below it to be transported along with the top component. In some cases, the loose coupling can fail while the top component is being manipulated, causing the other component(s) to separate from the top component and drop to the floor. Alternatively, the other components could stay coupled together and result in moving more components than necessary to a subsequent step in the manufacturing operation. Either result would be undesirable.

One solution to the aforementioned problem is to utilize a pneumatic device configured to draw air through multiple suction assemblies. The suction assemblies can be distributed across the pneumatic device so that suction, generated by a pneumatic system of the pneumatic device such as an air mover, is applied to multiple locations along a top component located atop a stack of other components. When the pneumatic device engages the top component, one or more of the suction assemblies can be configured to exert a force upon a central portion of the component while two or more of the suction assemblies can be configured to exert a different amount of force upon peripheral portions of the top component. The differential force exerted by the suction assemblies can cause the peripheral portions of the top component to bend away from the stack of other components. In this way, temporary couplings between the top component and the stack of components beneath can be severed. In some embodiments, one or more of the suction assemblies can take the form of a conventional suction cup or plunger, operable to attach to and retain a firm grip on the top component without the need for pneumatic suction.

One specific application where this type of pneumatic device can be employed is in removing a silicon wafer or solar cell from a stack of other solar cells. Because the solar cells are quite thin, commonly on the order of between 100 and 500 microns, bending the solar cells is quite feasible. Generally, the differential forces applied by the suction assemblies need only lift the periphery of the cell high enough to separate the periphery from the solar cells beneath it. In some embodiments, lifting the periphery about 1-2 mm above the center can be sufficient to obtain positive results. It should be noted that in the following portions of the detailed description that the term substrate is used to refer to the sheet-like components depicted in this disclosure. The term substrate is used to include the silicon substrate upon which the solar cell is based. The term can also include refer to any intermediate manufacturing state achieved by the silicon substrate as it is becomes a solar cell. It should also be noted that he described embodiments could be applied for destacking other sheet-like components, such as, e.g., different types of wafers or sub solar cells without departing from the spirit and scope of the disclosure.

These and other embodiments are discussed below with reference to FIGS. 1-7, however, those skilled in the art will readily appreciate that the detailed description given herein with respect to these figures is for explanatory purposes only and should not be construed as limiting.

Referring now to the drawing figures, FIG. 1 shows a perspective view of a manufacturing line 100 configured to transport stacks of substrates 102 from one location to another. The stacks of substrates 102 are supported by stack holders 104. Stack holders 104 define cut-aways that allow height adjustment mechanisms 106 to lift the stack of substrates 102 above stack holder 104. As substrates 102 are removed from the top of the stack by pneumatic device 108, height adjustment mechanisms 106 are configured to incrementally lift the stack of substrates 102 up so that the top of the stack remains in the same position. This prevents having to configure pneumatic device 108 with special sensors configured to determine where the top of the stack of substrates 102 is. Stack holder 104 can also include alignment guides 110, which are configured to keep the stack of substrates 102 from shifting laterally. In this way, height adjustment mechanism 106 and alignment guides 110 cooperate to maintain substrate 102 atop the stack of substrates 102 in the same position.

FIG. 1 also shows rail system 112 configured to maneuver pneumatic device 108 from a position over stack holders 104 to another location where additional manufacturing operations can be performed upon substrates 102. Rail system 112 is depicted, which includes support structures 114 positioned on either side of conveyor belt 116. Rail 118 rests on and is supported by support structures 114 and provides a mechanism by which pneumatic device 108 can move along the x-axis, thereby allowing pneumatic device 108 to pass over and across conveyor belt 116 and stack holders 104. Pneumatic device 108 is coupled to rail 118 by support arm 120. In some embodiments, support arm 120 can have a telescoping feature allowing pneumatic device 108 to be maneuvered along the y-axis. In some embodiments, pneumatic device 108 can include height adjustment component 122, which is coupled with plate 124. In some embodiments, height adjustment component 122 can be configured to rotate plate 124 of pneumatic device 108 about an axis parallel to the z-axis. Plate 124 is configured to provide a stable platform upon which suction assemblies 126 can be mounted. Suction assemblies 126 can include both a suction cup and an inlet port capable of receiving pneumatic tube 128. Pneumatic tube 128 can be attached to suction assembly 126 to create a vacuum effect at the suction cup end of each suction assembly 126. In some embodiments, release of substrate 102 can be expedited by reversing the flow of air through pneumatic tubes 128. In this way, instead of retaining substrate 102 the positive pressure can apply a force pushing substrate 102 away. This pneumatic force could be helpful in releasing substrate 102 in situations where vacuum pressure was leftover or where the suction cup adhesion between suction assemblies 126 and substrate 102 was too robust for gravity to overcome or would take too long to be overcome by the force of gravity alone. It should be noted that while a drop off location for substrate 102 is not shown, that any suitable surface could be configured to receive substrate 102 and perform additional processing thereon. For example, in some embodiments, pneumatic device 108 can be used to place substrates 1012 on another conveyor belt for further processing.

FIG. 2A shows a perspective view of pneumatic device 108 attached to substrate 102. In particular, height adjustment component 122 is depicted having lowered suction assemblies 126 into direct contact with a top surface of substrate 102. Once suction assemblies 126 contact substrate 102, air is sucked through pneumatic tubes 128 until the two ends of substrate 102 are secured to all four suction assemblies 126. In addition to suction assemblies 126, pneumatic device 108 also includes suction assemblies 202. Suction assemblies 202 can extend slightly farther from plate 124 than suction assemblies 126 so that when suction assemblies 126 are adhered to substrate 102 and begin lifting substrate 102 away from the stack, the lower position of suction assemblies 202 causes a central region of substrate 102 to remain in contact with the rest of the depicted substrates 102 while the peripheral region is pulled away from the stack. This results in separation of the edges of the top substrate 102 from the stack of substrates 102, thereby reducing any area dependent forces acting between substrates 102 in the stack. In some embodiments, a blower 204 can be configured along the side of stack holder 104 to blow air along the edge of the stack of substrates 102. By blowing air between substrate 102 and the other substrates 102 beneath it, additional separation can be created between substrates 102. In some embodiments, multiple blowers 204 can be arranged around a periphery the stack of substrates 102 to help encourage separation of the top substrate 102 from the substrates below it. FIG. 2B shows substrate 102 lifted clear of the stack of substrates 102. Due to the bend created in substrate 102 by pneumatic device 108, the rest of substrates 102 not engaged by pneumatic device 108 remain in place in the stack of substrates 102.

FIGS. 3A-3D show how height adjustment mechanisms 106 are configured to cooperate with stack holders 104 to keep the top of the stack of substrates 102 in a consistent position, such that as one substrate is removed, stack height is incremented upward to keep the top of the stack at a consistent elevation to enable proper operation of pneumatic device 108. FIG. 3A shows height adjustment mechanisms 106 in a lowered position that allows the conveyor belt to move a portion of stack holder 104 past height adjustment mechanisms 106 until height adjustment mechanisms 106 are aligned with cut-aways 302 defined by stack holders 104. FIG. 3B shows how height adjustment mechanisms 106 can move into an initial supporting position. In some embodiments, a sensor can be utilized that identifies the position of the top of the stack of substrates. For example, a laser range finder or equivalently accurate distance measurement tool can be used to identify the stack height. In other embodiments, height adjustment mechanisms 106 can be configured to set an initial height above stack holder 104 for the stack of substrates 102 based on the current weight of the stack of substrates 102. This can be accomplished by weighing the stack of substrates 102 and then calculating the height of the stack based on a known height and weight of each substrate. Regardless of the manner of sensing the height, height adjustment mechanisms 106 can then be configured to adjust the position of the stack of substrates 102 in accordance with the estimated height of the stack of substrates 102. The position of height adjustment mechanisms 106 as depicted in FIG. 3B can correspond to the stack of substrates 102 being a full stack of substrates 102.

FIG. 3C shows how as substrates 102 are removed from the top of the stack of substrates 102 that the stack of substrates is raised increasingly higher to maintain the top of the stack of substrates 102 at the same level. In applications where it is critical for the height to be exact, height adjustment mechanisms 106 can be configured to move higher after each substrate is removed. In embodiments in which the height of the top of the stack is less important, height adjustment mechanisms 106 can be configured to move upward after the removal of two or more substrates 102 from the stack of substrates 102. FIG. 3D shows a position of height adjustment mechanisms 106 just before the last of substrates 102 are removed. After the last substrate 102 is removed, height adjustment mechanisms 106 are configured to lower and allow the conveyor belt to maneuver the next stack holder 104 with its associated stack of substrates into position for pickup.

FIG. 4A-4D show front views of pneumatic device 108 as it picks up substrate 102. In particular, FIG. 4A shows how suction assemblies 202 are mounted lower on plate 124 than suction assemblies 126 by a distance 402. Distance 402 can be between 1 and 3 mm. Nuts 404 of each of suction assemblies 202 allow the vertical position of suction assemblies 126 and 202 to be changed by rotating nuts 404 to achieve a desired vertical position. Each of suction assemblies 202 and 126 can include internal springs configured to facilitate compression of the suction assemblies. Each of the suction assemblies can include a suction cup 406 or 408. In some embodiments, suction cups 406 and 408 can be the same, while in other embodiments suction cups 408 can be more pliable than suction cups 406. The greater pliability of suction cups 408 can allow suction cups 408 to accommodate bending of a periphery of one of substrates 102.

FIG. 4A also illustrates the similarities between suction assembly 126 and 202. In particular, suction assemblies 202 are depicted without pneumatic tubes 128. While suction assemblies 202 certainly could be outfitted with pneumatic tubes 128, this would be largely unnecessary as suction assemblies 202 function mainly to push a central region of substrate 102 while suction assemblies 126 pull up on peripheral regions of substrate 102. Adding pneumatic suction to suction assemblies 202 is largely unnecessary because the forces being exerted by suction assemblies 202 on substrate 102 act in a direction substantially opposite a direction than would be applied by suction being applied through suction assemblies 202. Omission of vacuum suction from suction assemblies 202 can be particularly important when an amount of pressure available to pneumatic device 108 is insufficient to spread across six suction assemblies. It should also be noted that suction assemblies 202 can differ structurally from suction assemblies 126 on account of not including pneumatic tube attachment feature 410. In some embodiments, rotation of pneumatic tube attachment feature 410 off of suction assembly 126 can result in suction assembly 126 having substantially the same structure as suction assembly 202. Consequently, pneumatic device 108 has an advantage in that each of the suction assemblies includes interchangeable parts. In other embodiments, suction assemblies 202 can have a different structure because suction assemblies need not have any axial channel for receiving suction.

FIG. 4B shows how suction assemblies 202, which come into contact with substrate 102 before suction assemblies 126, compress sufficiently to allow suction assemblies 126 to contact the top surface of substrate 102 and for each of suction cups 406 and 408 to adhere to substrate 102. By using weak springs within the suction assemblies, forces transmitted to substrate 102 can be sufficiently attenuated to prevent any damage when pneumatic device 108 contacts the stack of substrates 102; however, it should be noted that the internal springs should also be stiff enough to overcome the inherent rigidity in substrates 102.

FIG. 4C shows how pneumatic device 108 bends a periphery of a topmost substrate 102 upward and away from the stack of substrates 102 so that the periphery of substrate 102 is separated by a distance 412 from the stack of substrates 102 beneath it. In some embodiments, distance 412 can be substantially the same as the vertical offset between suction assemblies 202 and 126, illustrated by distance 402 in FIG. 4A. In other embodiments, the rigidity of substrates 102 can cause distance 412 to be substantially smaller than distance 402. By placing suction assemblies 202 proximate to suction assemblies 126, the amount of curvature induced in substrate 102 can be influenced greatly by minor variations in the vertical position of suction assemblies 202 with respect to suction assemblies 126. For example, placing suction assemblies 202 closer to the center of plate 124 can reduce the amount of curvature generated by the vertical offset, whereas moving suction assemblies 202 outboard and closer to suction assemblies 126 can increase the curvature produced by a given vertical offset. Movement of the suction assemblies closer together increases the resulting curvature for a given vertical offset on account of the reduction in lateral offset increasing the elevation angle between suction assemblies 202 and 126. This increased angle in turn increases the amount of curvature of substrate 102.

FIG. 4D shows substrate 102 lifted free of the stack of substrates. Of particular notice, FIG. 4D shows how the central region of substrate 102 between suction assemblies 202 takes on a slight curvature defined by the height difference and lateral offset between the suction assemblies. Subsequent to moving substrate 102 with pneumatic device 108 to its designated location, the air flowing through pneumatic tubes 128 can be reversed to create positive pressure that releases substrate 102 from pneumatic device 108.

FIGS. 5A-5D show different views of exemplary suction assembly 500, which is capable of carrying out the function of any of the aforementioned suction assemblies 126 or 202. In particular, it should be noted that FIG. 5A shows a side view of suction assembly 500 and how threading 502 is arranged along a central region of suction assembly 500. Threading 502 allows threaded nuts 404 to be translated along a longitudinal axis of suction assembly 502. In this way, suction assembly 500 can be maneuvered vertically with respect to a plate to which it is mounted. In some embodiments, a vertical position of suction assembly 500 with respect to a plate to which it is coupled can be set by calibration machinery. The narrow threads of threading 502 allow the vertical position of suction assembly 500 to be set with high precision. Suction assembly 500 can also include an internal spring disposed within suction assembly 500 that allows suction assembly 500 to be compressed. For example, segment 504 of suction assembly 500 can be received within a portion of segment 506, which has a slightly greater diameter than segment 504.

FIG. 5B shows a perspective view of suction assembly 500. Suction assembly 500 is depicted from an angle that shows how pneumatic tube attachment feature 410 defines inlet port 508. Inlet port 508 is configured to receive a pneumatic tube. Inlet port 508 leads into a channel that extends axially through suction assembly 500. In this way, positive pressure or vacuum supplied by a pneumatic tube disposed within inlet port 508 can travel axially through suction assembly 500 and out through an aperture defined by suction cup 408.

FIGS. 5C-5D shows a side view of suction assembly 500 that omits threaded nuts 404 and threading 502 in order to more clearly depict internal spring 510. FIG. 5C shows suction assembly 500 in an uncompressed state and FIG. 5D shows suction assembly 500 in a compressed state. Internal spring 510 accommodates compression of internal spring 510 and segment 504 recessing into the portion of suction assembly 500 that defines threading 502. In some embodiments, segment 506 can also be configured to recess into the portion of suction assembly 500 that defines threading 502. In other embodiments, internal spring 510 can be positioned within different portions of suction assembly 500.

FIGS. 6A-6D show alternative ways in which a pneumatic device can be used to lift substrate 102 off a stack of other substrates 102. It should be noted that pneumatic tubes have been removed for clarity purposes in FIGS. 6A-6D but could still be used to create suction FIG. 6A shows a perspective view of pneumatic device 602 removing substrate 102. This configuration is the one previously depicted and relies upon positioning two suction assemblies 202 inboard of four other suction assemblies to create a bend in substrate 102 about line of maximum deflection 604. More generally, suction assemblies 202 can be positioned within a footprint of a polygonal arrangement of suction assemblies 126 so that suction assemblies 202 can facilitate protrusion of a central portion of substrate 102.

FIG. 6B shows suction assemblies 126 in substantially the same position as shown in FIG. 6A. By moving suction assemblies 202 between each pair of suction assemblies 126 the bending motion can be substantially changed from the embodiment depicted in FIG. 6A. The result is substrate 102 bending in the opposite direction as shown in FIG. 6A about line of maximum deflection 604. It should be noted that suction assembly 126 could be instead configured with only two suction assemblies 126 and one suction assembly 202. The suction assemblies could be positioned in a line in front of height adjustment component 122 and still bend substrate 102 along line of maximum deflection 604.

FIG. 6C shows how suction assemblies 202 can be arranged along diagonal line of maximum deflection 604 of substrate 102. By engaging substrate 102 with suction assemblies 202 along diagonal line of maximum deflection 604 and with suction assemblies 126 at locations offset a fixed distance from both sides of diagonal line of maximum deflection 604, bending forces can be symmetrically distributed along substrate 102.

FIG. 6D shows how an alternative embodiment where pneumatic device 632 can be configured with three suction assemblies 126. The three suction assemblies extend through openings in plate 124 and are used to establish a plane substantially parallel to the top of the stack of substrates 102. FIG. 6D also illustrates how pushing assembly 634 is vertically offset lower than suction assemblies 126. Pushing assembly 634 can be substantially different than the suction assemblies 126 in that it does not have a suction cup at its end. Instead pushing member can include pushing member 636 with a shape configured to conform to a geometry of substrate 102 in its bent state. As depicted, pushing member 634 has a somewhat spherical shape able to spread stress evenly across its face. In some embodiments, pushing member 636 can have a wedge-shaped geometry that encourages substrate 102 to bend along line of maximum deflection 604. Once suction is applied to through suction assemblies 126, the peripheral portions of substrate 102 are pulled up so that substrate 102 bends along line of maximum deflection 604. In general, a pushing assembly 634 could be used to replace any one or more of suction assemblies 202 depicted above.

FIG. 7 shows a flow chart depicting a method for utilizing a pneumatic device to sequentially remove substrates from a stack of substrates. The pneumatic device includes multiple suction assemblies used to secure the substrate to the pneumatic device. A first group of at least three suction assemblies extend the same distance from a substantially planar plate of the pneumatic device and towards the stack of substrates. A second group of one or more additional suction assemblies also extend from the planar plate and towards the stack of substrates a distance generally 1 or 2mm greater than the first group of suction assemblies. At 702, a pneumatic device is pressed against a top substrate of the stack of substrates with a force sufficient to secure each of the suction assemblies to a substrate positioned atop a stack of other substrates. Springs within the suction assemblies allow the second group of substrates to compress so that the first group of suction assemblies can also engage substrate 102.

At 704, pneumatic tubes apply suction to the substrate through suction assemblies of the first group, thereby further strengthening the coupling between the pneumatic device and the top substrate. In some embodiments, the second group suction assemblies can be configured to receive positive pressure to apply additional force to a central portion of the substrate. In some embodiments, this added force can be used to tune the amount of bending in the substrate. For example, if a computer vision system were to identify a substrate clinging to the bottom of a substrate held by the pneumatic device, positive pressure could be delivered through the second group of suction assemblies in order to encourage separation of the clinging substrate. In some embodiments, a configuration capable of concurrently applying suction through the second group of suction assemblies and positive pressure through the first group of suction assemblies could include two different pneumatic systems. A pneumatic system can take the form of a compressor or air mover. In some embodiments, the pneumatic system attached to the first group of suction assemblies could be capable of only applying positive pressure through the first group of suction assemblies while the pneumatic system attached to the second group of suction assemblies could be configured to apply positive pressure and suction.

At 706, the pneumatic device is depicted as it is moving away from the stack of substrates and lifting the top substrate off the stack of substrates. As the pneumatic device moves away from the stack of substrates, the first group of suction assemblies would lift a periphery of the top substrate away from the stack of substrates, thereby beginning to bend the periphery of the top substrate away from the stack of remaining substrates. The speed at which the pneumatic device moves away from the stack can be modulated to discourage adhesion between the top substrate and the substrates beneath it. For example, a slower speed can be used until separation of the substrate from the stack is likely. It should be noted that in some embodiments modulation of speed would be unnecessary on account of the substantial separation of the substrate from the stack of substrates being sufficient to prevent any likelihood of unintentional coupling between the secured substrate and the remaining stack of substrates.

At 708, after the pneumatic device has moved the substrate to its new location, the vacuum suction applied through the pneumatic tubes can be removed so that the substrate can be released from the pneumatic device. In some embodiments, instead of simply ceasing the application of suction through the suction assemblies, pressure moving through the pneumatic tubes can be reversed so that positive pressure is applied to the substrate. This can be helpful in situations where the substrate could remain attached due to the coupling generated by the suction cups alone. Even when release is not necessary to release the substrate from the pneumatic device, the positive pressure can also help to make the release of the substrate more rapid so that the handling operation can be carried out more quickly. It should be noted that the springs disposed within the suction assemblies can help to cushion any force resulting from the substrate contacting another support surface just prior to release. In other embodiments, the substrate can be released and dropped a short distance before contacting a support surface.

The various aspects, embodiments, implementations or features of the described embodiments can be used separately or in any combination. Various aspects of the described embodiments can be implemented by software, hardware or a combination of hardware and software. For example, in some embodiments, a processor executing computer code can be configured to direct the actions taken by the pneumatic device. As described above, the actions taken can include applying suction to pick up the substrate, continuing to apply suction while transporting the substrate and ceasing the use of suction to release the substrate from the pneumatic device. In this way, the various installation steps described herein could therefore be carried out by a computing platform with instructions executed by the processor and carried out by machinery similar to that illustrated in FIG. 1.

Representative applications of methods and apparatus according to the present application are described above. These examples are being provided solely to add context and aid in the understanding of the described embodiments. It will thus be apparent to one skilled in the art that the described embodiments may be practiced without some or all of these specific details. In other instances, well known process steps have not been described in detail in order to avoid unnecessarily obscuring the described embodiments. Other applications are possible, such that the following examples should not be taken as limiting.

The foregoing description, for purposes of explanation, used specific nomenclature to provide a thorough understanding of the described embodiments. However, it will be apparent to one skilled in the art that the specific details are not required in order to practice the described embodiments. Thus, the foregoing descriptions of specific embodiments are presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the described embodiments to the precise forms disclosed. It will be apparent to one of ordinary skill in the art that many modifications and variations are possible in view of the above teachings. 

What is claimed is:
 1. A pneumatic device, comprising: a support structure; and a plurality of spring-loaded suction assemblies coupled to the support structure, the plurality of spring-loaded suction assemblies comprising: a first group of two or more spring-loaded suction assemblies extending a first distance from a surface of the support structure, and a second group of one or more spring-loaded suction assemblies extending a second distance from the surface of the support structure, the second distance being greater than the first distance.
 2. The pneumatic device of claim 1, wherein each spring-loaded suction assembly of the plurality of spring-loaded suction assemblies includes a suction cup at a distal end of the spring-loaded suction assembly.
 3. The pneumatic device of claim 2, wherein the suction cups associated with the first group have a different design than the suction cups associated with the second group.
 4. The pneumatic device of claim 1, wherein the first group of two or more spring-loaded suction assemblies is arranged in a pattern that defines a polygon and wherein the second group of one or more spring-loaded suction assemblies is positioned within the polygon.
 5. The pneumatic device of claim 1, wherein the second group is arranged along a line and wherein each of the spring-loaded suction assemblies of the first group is offset from the line by substantially the same distance.
 6. The pneumatic device of claim 1, further comprising an air mover.
 7. The pneumatic device of claim 6, wherein each suction assembly of the first group of suction assemblies includes a pneumatic tube configured to receive positive or negative pressure from the air mover.
 8. The pneumatic device of claim 1, wherein each spring-loaded suction assembly comprises an internal spring.
 9. A method of lifting a substrate off of a stack of substrates, the method comprising: engaging a peripheral portion of the substrate with a first group of suction assemblies of a pneumatic device; engaging a central portion of the substrate with a second group of suction assemblies of the pneumatic device; bending the peripheral portion of the substrate away from the stack of substrates using the first group of suction assemblies while the second group of suction assemblies keeps the central portion of the substrate in contact with the stack of substrates; and lifting the substrate off of the stack of substrates after bending the peripheral portion.
 10. The method of claim 9, wherein lifting the substrate comprises maintaining the bend in the substrate until the substrate is fully separated from the stack of substrates.
 11. The method of claim 9, wherein bending the peripheral portion of the substrate away from the stack of substrates comprises bending the substrate about a line of maximum deflection.
 12. The method of claim 9, wherein engaging the peripheral portion of the substrate comprises applying vacuum suction to the peripheral portion through the first group of suction assemblies.
 13. The method of claim 12, wherein engaging the central portion of the substrate does not include applying vacuum suction through the second group of suction assemblies.
 14. The method of claim 12, further comprising releasing the substrate from the pneumatic device by applying positive pressure to the substrate through the first group of suction assemblies.
 15. The method of claim 9, further comprising directing air between the substrate and the stack of substrates to help separate the substrate from the stack of substrates.
 16. The method of claim 9, wherein engaging the central portion of the substrate comprises positioning the second group of suction assemblies along a line of maximum deflection of the substrate.
 17. A pneumatic device, comprising: a support structure; a plurality of suction assemblies coupled to the support structure; a pushing assembly coupled to the support structure and extending farther away from the support structure than two or more of the plurality of suction assemblies; and an air mover configured to drive air through and draw air into the plurality of suction assemblies.
 18. The pneumatic device of claim 17, wherein the pushing member is a spring-loaded suction assembly.
 19. The pneumatic device of claim 17, wherein the pushing assembly comprises a pushing member configured to engage a substrate with a convex surface.
 20. The pneumatic device of claim 19, wherein the first group of suction assemblies is arranged along a periphery of the substantially planar support structure. 